This is a request for funding for an international symposium on the topic "Immunity, Drugs of Abuse and AIDS". This proposal is a new grant application for a symposium, which is the second one related to this subject following the successful one held in the Tampa Bay area December, 1989, entitled "Drugs of Abuse, Immunity and Immunodeficiency". That was a highly successful conference and it was recommended by all speakers and participants that a follow-up meeting should be held 2-3 yrs afterwards. Thus, this request is for funding of such a conference. It is now widely acknowledged there is a relationship between drugs of abuse as possible cofactors for AIDS and there is also a linkage between the immune and nervous systems, i.e., psychoneuroimmunology. In this regard, the relationship between drugs of abuse and immune functions is now considered a major area of interest for many biomedical scientists and clinicians. A large number of subjects who are at risk for AIDS are also abusers of drugs such as marijuana, cocaine, and opiates, as well as alcohol. Therefore, a major goal of the proposed application is to organize this symposium to bring together again internationally renown biomedical scientists to discuss not only what has been done in terms of examining the nature and mechanism of immune modulation by drugs of abuse such as marijuana, cocaine and opiates, but also important parameters which still must be examined in both man and experimental animals to define mechanisms whereby such agents influence immunity. Such drugs may contribute to AIDS development in human immunodeficiency virus (HIV) infected persons by serving as a source of virus (i.v. drug abusers) and as a cofactor which may depress immune functions. Relationship between effects of such drugs and AIDS on immunity and the neurological system is also a major aim of this proposed conference. Thus, this application specifically seeks funds for approximately 20 speakers (non-federal government speakers) for this meeting, including their transportation costs, costs for accommodation in the meeting hotel and other incidental expenses. Funds are also requested to defray the travel and housing costs for the four outstanding biomedical scientists from overseas invited as speakers. We also request a relatively small amount of funds to help defray the many expenses of printing announcements, programs, abstract booklets, etc., as well as mailing announcements. We are also requesting a minimum amount of funds for office expenses. We believe such a meeting will again, as in the past, be highly cost effective and an efficient method to bring together some of the world renown investigators in the areas of psychoactive drugs, immunity and AIDS.